The present invention relates to crime scene evidence, and more particularly, to a portable latent fingerprint fuming apparatus for developing white-colored crystallized fingerprints.
It is well known that human beings each have their own individualized fingerprints. It may well be said that no two fingerprints are alike. Consequently, whenever someone leaves their fingerprints behind at a crime scene, a suspect may be identified who has the same fingerprints.
Over the years, forensic technology permitted law enforcement technicians to effectively dust fingerprints and remove the dusted print from a particular surface or object with a clear tape. Fingerprints permit and attract dusting due to their ridges of residue, including oils, amino acids, moisture and fats. However, with dusting and taping, fingerprints can typically only be taken once and are highly susceptible to being damaged prior to fixation.
Consequently, forensic research over the years has developed glue fuming which is a chemical step recommended for almost all latent print processing techniques for nonporous objects or items. The item or object to be fumed is subjected to cyanoacrylate, which is commonly or generically termed super glue.
The cyanoacrylate or super glue is a quick bonding material that is further characterized by having an odoriferous eye and nose irritating vapor or toxic fume that reacts with trace amounts of latent fingerprint residues to develop a white-colored, hard, "petrified" print impression suitable for multiple powdering and lifting off with a tape or otherwise photographed.
Due to the harmful nature of the cyanoacrylate or super glue, glue fuming is most often conducted in an enclosed container, such as an aquarium or an enclosed plexiglass box. A cup of warm water is added to the inside of the aquarium to add humidity to the chamber to enhance crystallization of the latent print. A few drops of the liquid super glue are placed in a small dish or on a piece of aluminum foil within the aquarium. Thereafter the aquarium or container is closed for fuming which may take ten to fifteen minutes or longer depending on the humidity and the ambient temperature.
Fuming by this passive aquarium or container process is subject to a variety of problems. Too much fuming of the latent fingerprint will cover the entire surface of the item with a white residue and the ridges of the latent prints may actually be filled in. Over-fumed prints are difficult if not impossible to save because subsequent dusting or dye staining will adhere to the entire surface of the object or surface, obscuring the ridge detail. This mishap could easily occur when the technician is called away or forgets about the evidence in the fuming cabinet. Additionally, many objects, such as wadded up plastic materials or bags are difficult to be fumed because of the multiplicity of convolutions causing the inability to expose all surfaces to the vaporizing super glue. Large surfaces also do not lend themselves to fuming as they will not fit in fuming tanks. Also, fuming in tanks or aquariums often necessitates solvent cleaning of the fuming container making for an additional mess and further harmful vapors.
Recently, vacuum systems, that are very expensive and quite large, have been developed which make it next to impossible to over-fume objects and items placable within the fuming container. Also, there is no buildup of white residue on the inside of the fuming chamber or container. Additionally, glue fumes reach all sides and surfaces of the fumed object, whether crumpled or wadded, within the fuming chamber. Fuming by this method is typically accomplished by evacuating the chamber down to twenty-five inches of mercury and allowing the items to fume under vacuum for about twenty minutes. Thereafter, the latent prints are "locked on" the item for future print removal and study.
There is a need for a portable latent fingerprint fuming apparatus that will not only fume items and objects but even, uneven and curved nonporous surfaces without the need for expensive, large and complex vacuum systems.